A process for manufacturing a composite material comprising a functionalization of the substrate, which comprises treatment of said substrate with at least one first alcoholic solvent, functionalization of a first powder and formation of a first colloidal sol of said functionalized first powder in a second solvent, at least one application of a layer of said first colloidal sol of said first powder to the substrate, drying of said layer of said first colloidal sol and formation of a layer of first coating formed by said first colloidal sol, adherent to said substrate, by heating at a temperature above 50 C. and below 500 C.